MS hands notebook OEMs some $$$ to not keep OpenGL support up to date in effort to promote DirectX.
MS figures the way to implement this is to have OEMs require driver updates through themselves only.
OEMs fabricate reasons for why users should not be able to directly install reference graphics drivers with full OpenGL support for notebooks.

When pressed by users the GPU maker issue statements like:

“AMD (formerly ATI) introduced the concept of Catalyst Mobility which is a generic driver that works decently for most laptops. The only way we are able to do this is through permission by a laptop manufacturer (OEM) to include their device in the Catalyst
Mobility. We were the first company to provide graphics drivers for laptops to the general public, and we believe there is great value in this. At this point we only have permission from a few vendors and I personally wish more of them would let us. My suggestion
is you contact your manufacturer and ask them to have your laptop included in Catalyst Mobility. As for Vista specifically we do not have permissions yet, but as soon as we do we look forward to releasing Vista drivers for laptops.“

Since it wouldn't make any sense to have gaming laptops not support so many OpenGL games out there the only logical conclusion is that Microsoft must have a hand here!